Bumper for reducing pedestrian injury

ABSTRACT

A vehicle bumper system includes a beam, and an energy absorber with top and bottom horizontal sections and a mid-horizontal section. The horizontal sections form top and bottom nose portions that are semi-rigid but initially collapsible with a parallelogram motion that shifts the top and bottom portions vertically up (or down) upon-impact. Horizontal impact forces are converted in part to vertical forces during an initial stroke of a frontal impact, “catching” an impacted human being. Then during a further continuing impact stroke, the top and bottom horizontal sections provide a “throwing” action. End sections of the energy absorber extend around ends of a bumper beam, forming a collapsible corner that, during impact, initially absorbs energy at a low rate to “catch” a person, and then develops increasing lateral forces that “throw” the person during a continuing impact stroke.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.10/208,300 filed on Jul. 30, 2002 entitled BUMPER FOR REDUCINGPEDESTRIAN INJURY, now U.S. Pat. No. 6,685,243.

BACKGROUND

The present invention relates to bumpers for passenger vehicles designedto reduce pedestrian injury upon impact, and more particularly relatesto a bumper having an energy absorber optimized to provide a relativelysoft initial impact and a “throwing” force after initial impact to apedestrian struck by the bumper.

Automotive bumper systems in the United States have been designed forresistance to damage at low and high vehicle speeds and for high-energyabsorption at high impact speeds. Recently, pedestrian safety has begunto receive increasing attention. However, design of bumpers forpedestrian safety is complicated by several conflicting functionalrequirements. Obviously, the human body cannot withstand high-energyimpacts nor sharp impacts without substantial damage to muscle and bonetissue. However, it is difficult to reduce the magnitude and rate ofenergy transfer from a bumper to a pedestrian upon impact, especiallyimmediate transfer of energy from a “sharp” impact, because vehiclebumpers are usually limited to a relatively short stroke by componentsbehind the bumper, such as a radiator and other engine components, andalso limited by other front-end components and supporting structure.This is especially true of smaller and more compact vehicles. Further,the bumpers must be made of strong materials in order to maintain theirshape and appearance over time, and to provide their primary function ofbeing a “bumper” for the vehicle to push away items and to preventdamage to the vehicle. The problems are further complicated byaerodynamic designs, where corners of the bumper system are swept andcurved back into the vehicle fenders, which further limits bumpersstrokes and the bumper's ability to collapse or flex. Also, the problemis compounded by the fact that bumpers are at knee-height, such thatpedestrian-related vehicular accidents often involve trauma to thepedestrian's knees. Joints and exposed bones are particularly prone toinjury upon impact.

Accordingly, a bumper system is desired solving the aforementionedproblems and having the aforementioned advantages.

SUMMARY OF THE PRESENT INVENTION

In one aspect of the present invention, a bumper system for a vehicleincludes a beam adapted for attachment to a vehicle, and an energyabsorber engaging a face of the beam. The energy absorber has a tophorizontal section defined by a top wall and an upper-mid wall connectedby an upper-front wall, and also has a bottom horizontal section definedby a bottom wall and a lower-mid wall connected by a lower-front wall,and still further has a middle horizontal section defined by a mid-frontwall connecting the upper-mid wall and the lower-mid wall. The top andbottom horizontal sections include top and bottom front nose portionsthat extend forward of the mid-front wall and that define a horizontalchannel therebetween in front of the mid-front wall. The front noseportions are configured to provide a first level of energy absorptionduring an initial impact stroke that collapses one or both of the frontnose portions, with the top, middle, and bottom horizontal sectionsproviding a higher second level of energy absorption during a continuingimpact stroke that collapses the energy absorber against the face of thebeam. A fascia covers the energy absorber and the beam. By thisarrangement, during an initial front impact stroke, the top and bottomfront nose portions provide a relatively low-energy absorption that“catches” an impacted object such as a knee of a human being, and thenduring a further continuing impact stroke, the top, middle, and bottomhorizontal sections crush to provide an increased energy absorption.

In another aspect of the present invention, a bumper system for avehicle includes a beam adapted for attachment to a vehicle and having alongitudinal curvature that, when viewed from above in a vehicle-mountedposition, is shaped to match an aerodynamic curvilinear shape of a frontof the vehicle. The bumper system further includes an energy absorberengaging a face of the beam. The energy absorber has a top horizontalsection defined by a top wall and an upper-mid wall connected by anupper-front wall, and has a bottom horizontal section defined by abottom wall and a lower-mid wall connected by a lower-front wall, suchthat the top and bottom horizontal sections include top and bottom frontnose portions that extend forwardly. The top and bottom nose portionseach are semi-rigid but are collapsible with a parallelogram motion thatshifts one or both of the top and bottom front walls vertically, suchthat horizontal impact forces are converted at least in part to avertical force upon receiving a horizontal frontal impact during aninitial stroke of the frontal impact. By this arrangement, during afirst part of the frontal impact, the top and bottom front nose portionsprovide a relatively low-energy absorption that “catches” an impactedobject such as a knee of a human being, and then during a furthercontinuing impact stroke, the top and bottom horizontal sections crushto provide an increased energy absorption.

In still another aspect of the present invention, a method comprisessteps of constructing a bumper system including a stiff beam, and anenergy absorber on a face of the beam. The energy absorber has top,middle, and bottom sections, with the top and bottom sections definingnose portions that extend forward of the middle section. The nosesections define a space therebetween in front of the middle section, thetop and bottom nose sections being constructed to deflect with aparallelogram motion upon impact and that shift at least one of the noseportions vertically with a parallelogram motion in response to an impactdirected horizontally against a front of the bumper system, wherebyenergy directed against a knee of an impacted person is converted into athrowing force that directs the person in a direction generallyperpendicular to the line of impact and away from the vehicle bumpersystem.

The objects of the present invention include providing a bumper systemadapted to initially “catch” a person during an initial phase of impact,with less energy and forces being transmitted to the person and/or theforces being transmitted at a slower rate during the initial phase, andhence less injury being likely. The objects further include re-orientingthe impact forces transmitted to the person from a line parallel thedirection of impact to a direction upward or downward (in the case of afront impact) or laterally (in the case of a corner impact). By theseactions, the impacted person is initially “caught” and then “thrown” ina direction away from the line of impact, thus reducing injury and alsoreducing damage to the vehicle bumper system.

These and other aspects, objects, and features of the present inventionwill be understood and appreciated by those skilled in the art uponstudying the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side elevational view of a bumper system on a vehicleembodying the present invention;

FIG. 2 is a perspective view of the bumper system shown in FIG. 1;

FIGS. 3–5 are enlarged views of the bumper system shown in FIG. 1, FIG.3 showing the bumper system before a frontal impact against a person'sknee and leg,

FIG. 4 showing the bumper system during an initial part of the frontalimpact against the knee and leg, and

FIG. 5 showing the bumper system during a continuing part of the frontalimpact;

FIG. 6 is a plan view of the bumper system shown in FIG. 1, including aphantom line showing an initial collapse/deflection of the nose portionsof the energy absorber, a dashed line showing secondary crushing of theenergy absorber, and a dash-dot-dash line showing deformation of thebumper beam to a straightened condition, FIG. 6 also showing a dottedline depicting the result of using the present energy absorber with ahighly rigidified beam that does not collapse nor substantially deform;

FIG. 7 is a force-deflection curve showing energy absorption during animpact against the bumper system of FIG. 1; and

FIGS. 8–10 are schematic plan views of a corner impact sequence, FIG. 8showing the corner of the bumper system immediately prior to cornerimpact, FIG. 9 showing the corner during an initial part of the cornerimpact, and FIG. 10 showing the corner during the continuing part of thecorner impact.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A vehicle bumper system 20 (FIGS. 1–2) includes a beam 21, and an energyabsorber 22 with top and bottom horizontal sections 23, 24, and a middlehorizontal section 25. The top and bottom horizontal sections 23–24 formtop and bottom nose portions 26 and 27 that are semi-rigid butcollapsible with a parallelogram motion that shifts the top and bottomportions 26 and 27 vertically up (or down) upon impact. As a result,horizontal impact forces 30 are converted in part to vertical forces 31during an initial stroke of a frontal impact (FIG. 4), in effect“catching” the knee 29′ (FIG. 4) of a human 29 during a collision. Upona continuing impact stroke (FIG. 5), the top and bottom horizontalsections 23–24 provide a “throwing” action, as shown by increasingforces 31 and 31′. During the continuing impact stroke, the horizontalsections 23–25 also crush and provide increased energy absorption, asshown by FIG. 5. The combination of these forces 31 and 31′ “throw” theimpacted human 29 upward in a direction off the bumper beam 21. Amajority of the force 31 is upward due to a majority of the person'sweight being above the person's knees. However, it is noted that thereis a component of downward vertical forces 31′, as shown in FIG. 5.

A length of the energy-absorbing stroke of the bumper system 20 (FIG. 6)is extended by use of the beam 21, which has a shallow cross sectionthat takes up less space due to its small depth. Specifically, the beam21 has a height-to-depth ratio of at least about 3:1, and morepreferably of at least about 4:1 or greater, such that the beam 21flexes and deforms more readily than many existing bumper beams. Ashallowness of the beam reduces the amount of space taken up by the beam21 in front of the radiator of the vehicle, and also the combination ofthe energy absorber 22 and the dynamics of the energy absorption uponimpact and crush cause the beam 21 to flex to “catch” a person with ahammock-like action, thus providing reduced injury to pedestrians uponimpact. Further, due to the increased stroke, the energy absorption isnot decreased an unacceptable amount for many vehicles. It is notedthat, although the beam 21 can be bent with a “hammock-like action”, thebeam 21 has considerable strength, such that it flexes and deforms onlyupon substantial impact and forces being generated. Further, thesefunctional characteristics can be varied by design of the bumper system20, as discussed below.

The energy absorber 22 also has end sections 34 (FIG. 8) that extendaround ends of the bumper beam 21, forming a collapsible corner that,during impact, initially absorbs energy at a relatively low rate fromforces of impact 30 such that it basically “catches” an impacted person.During the initial impact stroke (FIG. 9), the end section 34 alsotorsionally collapses in direction 36 as it absorbs energy along thelines 37, with a rear portion 38 of the energy absorber 22 slidinglyengaging a side of the mount 39. During the continuing impact stroke(FIG. 10), the energy absorber 22 develops increasing lateral forcesthat “throw” the person in a direction 39′ sideways away from thevehicle during the continuing impact stroke.

The illustrated beam 21 (FIG. 3) is a roll-formed channel, and includesa transverse cross section defining a back-and-forth snake-like shape.It is contemplated that other channels can be used, such as extruded orstamped channels, or molded channels, and further that differentcross-sectional shapes can be used without departing from a scope of thepresent invention. The present cross section includes a center wall 40;opposing transverse flanges 41, 42 that extend forwardly from each edgeand define a channel 43; top and bottom walls 44, 45 that extendupwardly and downwardly from flanges 41, 42, respectively; and top andbottom edge flanges 46, 47 that extend rearwardly from top and bottomwalls 44, 45, respectively. The front face of beam 21 defines a shapeadapted to mateably engage a rear surface of the energy absorber 22,with the channel 43 engaging a ridge 63 on the energy absorber 22 toprovide an “anchor” for preventing the energy absorber 22 from slidingup over the beam 21 (or down under the energy absorber 22) during afront impact. Apertures or detents 48 are formed in the top and bottomedge flanges 46, 47, for receiving protruding hooks 49 on the energyabsorber 22 to temporarily hold the energy absorber 22 on the beam 21during subassembly. In assembly, a fascia 50 is positioned on the bumpersystem 20, either before or during assembly of the bumper system 20 to avehicle.

The top horizontal section 23 of the energy absorber 22 (FIG. 3)includes a top wall 52 and an upper-mid wall 53 connected by anupper-front wall 54. The bottom horizontal section 24 includes a bottomwall 55 and a lower-mid wall 56 connected by a lower-front wall 57. Themid-horizontal section 25 includes a mid-front wall 58 that connects theupper-mid wall 53 and the lower-mid wall 56. The mid-front wall 58 isrecessed rearwardly from the front walls 54 and 57 about aninch-and-a-half or two inches, such that the top and bottom nosesections 26 and 27 protrude forwardly of the mid-front wall 58. Further,the half of front walls 54 and 57 that are closest to wall 58 are angledinwardly to form an enlarged “mouth” or entrance to the channel 58′, asdescribed below. Further, the mid-front wall 58 has rectangularapertures formed therein. Vertical/fore/aft reinforcing walls 59 extendtransversely between the walls 52, 53, 55, 56 at edges of the aperturesand form box-like sections with walls 52, 53, 55, 56 that act tostabilize the walls relative to each other. The walls 52–59 can becontinuous to form a solid grid of honeycomb shapes, or can bediscontinuous and/or include apertures. By making these variations,different impact strengths and energy absorbing characteristics can beachieved in the energy absorber 22. Also, material composition and wallthicknesses can be varied to provide different energy absorbingcharacteristics.

When the energy absorber 22 is in a vehicle-mounted position, the walls52, 53, 55, 56 extend generally in a horizontal plane and from side toside of the vehicle. The walls 52, 53, 55, 56 as illustrated extend in afore/aft direction and are wave shaped or corrugated for increasedimpact strength, but it is contemplated that other shapes for the wallsare possible. The front walls 54 and 57 extend generally vertically andare coplanar and parallel, with the exception that they include angledportions that lead into channel 58′, and further, they are curved whenviewed from above to match an aerodynamic front shape of the vehicle.The mid-front wall 58 wall extends generally parallel to the front walls54 and 57, but is spaced rearwardly about an inch-and-a-half or twoinches. By this arrangement, it connects the top and bottom noseportions 26 and 27 to stabilize the nose portions 26 and 27, but so thatthe nose portions 26 and 27 are able to flex independently with aparallelogram motion (compare FIGS. 3–5). The illustrated mid-front wall58 has rectangular apertures 60 formed therein that are periodicallylocated along the mid-front wall 58. The apertures 60 are bounded bywalls 53 and 55 on their top and bottom, and are bounded by verticalwalls 59 on their side edges, such that walls 53, 55, and 59 formbox-shaped sections around each aperture 60. A rear wall 61 is formedalong a rear of the energy absorber 22. The rear wall 61 along with arear half inch of the walls 53, 54, 55, 56 forms the ridge 63 thatmateably engages the channel 43 on the beam 21. The rear wall 61 isaligned with each of the apertures 60, so-that the molding die formaking the energy absorber 22 can be made without pulls and cams andwithout moving die parts for making blind surfaces.

The top and bottom front nose portions 26 and 27 extend forward of themid-front wall 57 and define the channel 58′ therebetween in front ofthe mid-front wall 57. The front nose portions 26 and 27 are configuredto provide a first level of energy absorption during an initial impactstroke that collapses one or both of the front nose portions 26 and 27with a parallelogram-like motion. (Compare FIGS. 3–4). Notably, theparallelogram-like motion provides some energy absorption due to thecrumpling effect of the parallelogram motion on the reinforcing walls 59and also due to the bending forces absorbed by walls 53, 54, 56, and 57.However, a focus of the forces is in the parallelogram action of thenose portions 26 and 27 in combination with a columnar strength of thewalls 53, 54, 56, 57, which results in a significant percentage of thehorizontal forces of initial impact being converted into vertical forces31. Initially, a pedestrian's knee 29′ enters the channel 58′ andstrikes nose portions 26 and 27, causing them to deflect vertically(FIG. 4). As the impact stroke continues (FIG. 5), the top, mid andbottom horizontal sections 23–25 provide a higher second level of energyabsorption as the energy absorber 22 crushes and collapses against theface of the beam 21.

The fascia 50 extends over and covers the beam 21 and the energyabsorber 22. The fascia 50 includes a section of material that extendsbetween the upper and lower nose portions across the channel. The fascia50 cooperates with the nose portions during a front impact to facilitateand help cause the parallelogram motion.

FIGS. 6–7 illustrate a second way in which the present bumper systemprovides reduced injury to pedestrians. In the present bumper system 20(FIG. 6), the impact results in sequential deflection distances 70, 71,72, and 73. Upon impact, the nose portions 26 and 27 of the energyabsorber 22 initially bend with a parallelogram-type motion, whichresults in deflection of a front face of the bumper system a rearwarddistance 70. As the impact continues, the energy absorber 22 is crushedagainst a face of the beam 21 an additional distance 71. As the impactcontinues, the beam 21 is deformed an additional distance 72 toward astraightened condition between the vehicle mounts 39. The last distance73 represents a distance of deflection as the mounts 39 telescopinglycrush/collapse, and as the bumper beam 21 and energy absorber 22 aredriven rearwardly toward the vehicle radiator 75. The distances 70–73are represented on the graph of FIG. 7 by line segments 76–79, withenergy absorption being represented by the area under the curve formedby the line segments 76–79. It is noted that the energy absorber 22 canbe used on a tubular rigid beam 21′ that does not tend to bend, but insuch event, the bumper system would take up a dimension 74 and alsowould only collapse a total of distances 70, 71, and 73′ (since the beam21′ would not bend straight).

As noted above, the energy absorber 22 is adapted for corner impact byincorporating of the end sections 34 (FIG. 8) that extend around ends ofthe bumper beam 21. The end sections 34 form a collapsible corner that,during impact, initially absorbs energy at a relatively low rate fromforces of corner impact 35 such that it basically “catches” a knee of animpacted person. During the initial impact stroke (FIG. 9), the endsection(s) 34 also torsionally collapse in direction 36 as it absorbsenergy along the lines 37, with a rear portion 38 of the energy absorber22 slidingly engaging a side of the mount 39. During the continuingimpact stroke (FIG. 10), the energy absorber 22 develops increasinglateral forces in direction 39′ that “throw” the person sideways awayfrom the vehicle during the continuing impact stroke.

More specifically, the end section 34 of the energy absorber 22 includesan enlarged free end portion 75 and a transition portion 76 connectingthe free end portion 75 to an end of the middle or center section of theenergy absorber 22. The transition portion 76 includes a trapezoidallyshaped rearwardly-extending portion 78 that extends rearwardly to alocation adjacent an outer side of the mount 39. A honeycomb-shaped boxsection 79 is located outward of the trapezoidally shaped portion 78,and includes a first side connected to the trapezoidally shaped portion78, and a second side connected to the free end portion 75.

During an initial phase of an impact, impact forces from the impactingbody 80 are directed along a line of force, such as line of force 35,into the end section 34. The forces are transmitted along lines 37 and82 through the honeycomb-shaped box section 79, and along line 83 in thetrapezoidally shaped portion 78. The trapezoidally shaped portion 78engages a side of the mount 39, and slides rearwardly along the mount 39in direction 83 as the crash progresses. During a further part of theinitial phase of impact (FIG. 8), the trapezoidally shaped portion 78and the honeycomb-shaped box section 79 compress in a manner causing thefree end portion 75 to rotate rearwardly along the line 36. As thisoccurs, the honeycomb-shaped box section 79 compresses in a direction82. Also, the forces associated with the impacting body 80 begin tolessen in the direction of impact (see the shortened arrow 35′) and theforces are redirected along the line 39′ as the end section 34 resiststhe corner impact. As the impact continues (FIG. 10), the free endsection 75 bends further in direction 36. However, the honeycomb-shapedbox section 79 rebounds in a direction 39′, adding to the redirectedforces 39″ and still further reducing the forces 35′ of the impactingbody 80 against the end section 34. A result is that the impacting body80 is “thrown” away from the vehicle by increasing redirected forces 39′and 39′

To summarize, each of the transition portions 76 initially provide arelatively low-energy absorption and further are torsionally crushed sothat the enlarged free end portion 75 swings rearward and “catches” animpacted object such as a human being. The transition portions 76 thenreact during a further continuing part of the bumper stroke, such thatthe transition portions 76 provide increased energy absorption andcounteractive forces such that the free end portion pushes the impactedobject away both due to lateral resistive forces developed in the energyabsorber non-parallel a line of impact and also due to sliding of theimpacted object along an inclined surface of the free end portion.

It is to be understood that variations and modifications can be made onthe aforementioned structure without departing from the concepts of thepresent invention, and further it is to be understood that such conceptsare intended to be covered by the following claims unless these claimsby their language expressly state otherwise.

1. A bumper system for a vehicle comprising: a beam for attachment to avehicle; an energy absorber engaging a face of the beam; the energyabsorber having a top horizontal section defined by a top wall and anupper-mid wall connected by an upper-front wall, and having a bottomhorizontal section defined by a bottom wall and a lower-mid wallconnected by a lower-front wall, and further having a middle horizontalsection defined by a mid-front wall connecting the upper-mid wall andthe lower-mid wall, the top and bottom horizontal sections including topand bottom front nose portions that extend forward of the mid-front walland that define a horizontal channel therebetween in front of themid-front wall; the front nose portions being configured to provide afirst level of energy absorption during an initial impact stroke thatcollapses one or both of the front nose portions, and the top, middle,and bottom horizontal sections providing a higher second level of energyabsorption during a continuing impact stroke that collapses the energyabsorber against the face of the beam; and a fascia covering the energyabsorber and the beam; whereby, during an initial front impact stroke,the top and bottom front nose portions provide a relatively low-energyabsorption that contacts an impacted object, and then during a furthercontinuing impact stroke, the top, middle, and bottom horizontalsections crush to provide an increased energy absorption.
 2. The bumpersystem defined in claim 1, wherein the top and bottom walls define wavyand undulating surfaces.
 3. The bumper system defined in claim 1,wherein the beam comprises an open channel having a height-to-depthratio of at least 3:1.
 4. The bumper system defined in claim 1, whereinthe beam is rollformed.
 5. The bumper system defined in claim 1, whereinthe beam face defines a longitudinal forwardly-facing recess, andwherein the energy absorber includes a rearwardly-extending protrudingridge that extends into the forwardly-facing recess.
 6. The bumpersystem defined in claim 5, wherein the middle horizontal section of theenergy absorber includes the rearwardly-extending protruding ridge. 7.The bumper system defined in claim 1, wherein the top and bottom noseportions are semi-rigid but collapsible with a parallelogram motion thatshifts one or both of the upper and lower front walls vertically, suchthat horizontal impact forces are converted at least in part to avertical force upon receiving a horizontal frontal impact.
 8. The bumpersystem defined in claim 7, wherein the top nose portion collapses with aparallelogram motion that shifts the upper-front wall upward during animpact.
 9. A bumper system for a vehicle comprising: a beam forattachment to a vehicle and having a longitudinal curvature that, whenviewed from above in a vehicle-mounted position, is shaped to match anaerodynamic curvilinear shape of a front of the vehicle; an energyabsorber engaging a face of the beam; the energy absorber having a tophorizontal section defined by a top wall and an upper-mid wall connectedby an upper-front wall, and having a bottom horizontal section definedby a bottom wall and a lower-mid wall connected by a lower-front wall,the top and bottom horizontal sections including top and bottom frontnose portions that extend forwardly; the top and bottom front noseportions each being semi-rigid but collapsible with a parallelogrammotion that shifts one or both of the upper-front and lower-front wallsvertically, such that horizontal impact forces are converted at least inpart to a vertical force upon receiving a horizontal frontal impactduring an initial stroke of the frontal impact; and whereby, during afirst part of the frontal impact, the top and bottom front nose portionsprovide a relatively low-energy absorption that contacts an impactedobject, and then during a further continuing impact stroke, the top andbottom horizontal sections crush to provide an increased energyabsorption.
 10. The bumper system defined in claim 9, wherein the topand bottom walls are wavy.
 11. The bumper system defined in claim 9,wherein the beam comprises an open channel having a height-to-depthratio of at least 3:1.
 12. The bumper system defined in claim 9, whereinthe beam is rollformed.
 13. The bumper system defined in claim 9,wherein the beam face includes a longitudinal forwardly-facing recess,and the energy absorber includes a rearwardly-extending protruding ridgethat extends into the forwardly-facing recess.
 14. The bumper systemdefined in claim 13, wherein the energy absorber includes amid-horizontal section between the top horizontal section and the bottomhorizontal section, and wherein the mid-horizontal section of the energyabsorber includes the rearwardly-extending protruding ridge.
 15. Abumper system for a vehicle comprising: a bumper beam for attachment toa vehicle; and an energy absorber attached to a face of the bumper beam,the energy absorber including at least one section having parallel upperand lower walls that extend generally perpendicular to the face of thebumper beam and having a main front wall and an angled front wallconnecting a front edge of the upper and lower walls, the main frontwall and the angled front wall forming a non-planer front surface that,upon a front impact against a pedestrian's knee, causes a structuralcollapse where the upper and lower walls flex with a parallelogrammotion, the parallelogram motion redirecting and converting an impactforce that is initially horizontal against the knee into an upwardvertical force.
 16. The bumper system defined in claim 15, wherein theupper and lower walls each have a fore-to-aft horizontal length that issubstantially longer than a height of the main front wall and angledfront wall, thus assisting in the parallelogram motion.
 17. The bumpersystem defined in claim 15, wherein the at least one section includes atleast an upper horizontal section and a lower horizontal section, eachhaving a set of walls including the main front, angled front, upper andlower walls.
 18. The bumper system defined in claim 17, includingstabilizing walls that extend between the lower wall of the upperhorizontal section and the upper wall of the lower horizontal section,and wherein the upper and lower horizontal sections extend forward ofthe stabilizing walls to form upper and lower nose portions,respectively, with a forwardly facing channel therebetween.
 19. Thebumper system defined in claim 18, including a fascia extending over andcovering the beam and the energy absorber, the fascia including asection of material that extends between the upper and lower noseportions across the channel, the fascia cooperating with the noseportions during a front impact to facilitate and help cause theparallelogram motion.
 20. A bumper system for a vehicle comprising: abumper beam for attachment to a vehicle; and an energy absorber attachedto a face of the bumper beam, the energy absorber including at least onesection having parallel upper and lower walls that extend generallyperpendicular to the face of the bumper beam and having a front wall;the upper and lower walls being elongated and longer than the front walland further the upper and lower walls and the front wall being joined tocollapse with a parallelogram motion so that, upon a front impactagainst a pedestrian's knee and leg, the upper and lower walls flex witha parallelogram motion, the parallelogram motion redirecting andconverting impact forces that are initially horizontal against the kneeinto vertical forces less damaging to the pedestrian's knee and leg. 21.The bumper system defined in claim 1, wherein at least one of the topand bottom front nose portions includes a hollow area.
 22. The bumpersystem defined in claim 9, wherein at least one of the top and bottomfront nose portions includes a hollow area.
 23. The bumper systemdefined in claim 15, wherein the at least one section includes a hollowarea.
 24. The bumper system defined in claim 20, wherein the at leastone section includes a hollow area.
 25. The bumper system defined inclaim 1, wherein the walls include inner and outer surfaces.
 26. Thebumper system defined in claim 9, wherein the walls include inner andouter surfaces.
 27. The bumper system defined in claim 15, wherein thewalls include inner and outer surfaces.
 28. The bumper system defined inclaim 20, wherein the walls include inner and outer surfaces.